Insulin therapy as a precipitating factor congestive heart failure: presentation of clinical cases and review of the literature

We describe the appearance, within a few weeks from the beginning of insulin therapy, of signs and symptoms of congestive heart failure in three diabetic patients with known cardiac disease (one with aortic stenosis, one with hypertensive heart disease and one with ischemic heart disease), who however had never previously shown signs of heart failure. Reduction of the dose of insulin, along with a moderate diuretic therapy, led to resolution of clinical condition. Sodium retention and increased vascular permeability by insulin could be the causes of this phenomenon. In clinical practice it is necessary to remember that the beginning of insulin treatment could exacerbate left ventricular dysfunction to an overt heart failure. Future studies should evaluate whether insulin therapy plays a negative role in the long-term prognosis of patients with asymptomatic left ventricular dysfunction, as it has already been hypothesized in those with overt heart failure.